includes/api/ApiMain.php

   1 <?php
   2
   3 /*
   4  * Created on Sep 4, 2006
   5  *
   6  * API for MediaWiki 1.8+
   7  *
   8  * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License along
  21  * with this program; if not, write to the Free Software Foundation, Inc.,
  22  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23  * http://www.gnu.org/copyleft/gpl.html
  24  */
  25
  26 if (!defined('MEDIAWIKI')) {
  27         // Eclipse helper - will be ignored in production
  28         require_once ('ApiBase.php');
  29 }
  30
  31 /**
  32  * This is the main API class, used for both external and internal processing.
  33  * When executed, it will create the requested formatter object,
  34  * instantiate and execute an object associated with the needed action,
  35  * and use formatter to print results.
  36  * In case of an exception, an error message will be printed using the same formatter.
  37  *
  38  * To use API from another application, run it using FauxRequest object, in which
  39  * case any internal exceptions will not be handled but passed up to the caller.
  40  * After successful execution, use getResult() for the resulting data.
  41  *
  42  * @addtogroup API
  43  */
  44 class ApiMain extends ApiBase {
  45
  46         /**
  47          * When no format parameter is given, this format will be used
  48          */
  49         const API_DEFAULT_FORMAT = 'xmlfm';
  50
  51         /**
  52          * List of available modules: action name => module class
  53          */
  54         private static $Modules = array (
  55                 'login' => 'ApiLogin',
  56                 'logout' => 'ApiLogout',
  57                 'query' => 'ApiQuery',
  58                 'expandtemplates' => 'ApiExpandTemplates',
  59                 'parse' => 'ApiParse',
  60                 'opensearch' => 'ApiOpenSearch',
  61                 'feedwatchlist' => 'ApiFeedWatchlist',
  62                 'help' => 'ApiHelp',
  63                 'paraminfo' => 'ApiParamInfo',
  64         );
  65
  66         private static $WriteModules = array (
  67                 'rollback' => 'ApiRollback',
  68                 'delete' => 'ApiDelete',
  69                 'undelete' => 'ApiUndelete',
  70                 'protect' => 'ApiProtect',
  71                 'block' => 'ApiBlock',
  72                 'unblock' => 'ApiUnblock',
  73                 'move' => 'ApiMove',
  74                 'edit' => 'ApiEditPage',
  75                 #'changerights' => 'ApiChangeRights'
  76                 # Disabled for now
  77         );
  78
  79         /**
  80          * List of available formats: format name => format class
  81          */
  82         private static $Formats = array (
  83                 'json' => 'ApiFormatJson',
  84                 'jsonfm' => 'ApiFormatJson',
  85                 'php' => 'ApiFormatPhp',
  86                 'phpfm' => 'ApiFormatPhp',
  87                 'wddx' => 'ApiFormatWddx',
  88                 'wddxfm' => 'ApiFormatWddx',
  89                 'xml' => 'ApiFormatXml',
  90                 'xmlfm' => 'ApiFormatXml',
  91                 'yaml' => 'ApiFormatYaml',
  92                 'yamlfm' => 'ApiFormatYaml',
  93                 'rawfm' => 'ApiFormatJson',
  94                 'txt' => 'ApiFormatTxt',
  95                 'txtfm' => 'ApiFormatTxt',
  96                 'dbg' => 'ApiFormatDbg',
  97                 'dbgfm' => 'ApiFormatDbg'
  98         );
  99
 100         private $mPrinter, $mModules, $mModuleNames, $mFormats, $mFormatNames;
 101         private $mResult, $mAction, $mShowVersions, $mEnableWrite, $mRequest, $mInternalMode, $mSquidMaxage;
 102
 103         /**
 104         * Constructs an instance of ApiMain that utilizes the module and format specified by $request.
 105         *
 106         * @param $request object - if this is an instance of FauxRequest, errors are thrown and no printing occurs
 107         * @param $enableWrite bool should be set to true if the api may modify data
 108         */
 109         public function __construct($request, $enableWrite = false) {
 110
 111                 $this->mInternalMode = ($request instanceof FauxRequest);
 112
 113                 // Special handling for the main module: $parent === $this
 114                 parent :: __construct($this, $this->mInternalMode ? 'main_int' : 'main');
 115
 116                 if (!$this->mInternalMode) {
 117
 118                         // Impose module restrictions.
 119                         // If the current user cannot read,
 120                         // Remove all modules other than login
 121                         global $wgUser;
 122
 123                         if( $request->getVal( 'callback' ) !== null ) {
 124                                 // JSON callback allows cross-site reads.
 125                                 // For safety, strip user credentials.
 126                                 wfDebug( "API: stripping user credentials for JSON callback\n" );
 127                                 $wgUser = new User();
 128                         }
 129
 130                         if (!$wgUser->isAllowed('read')) {
 131                                 self::$Modules = array(
 132                                         'login'  => self::$Modules['login'],
 133                                         'logout' => self::$Modules['logout'],
 134                                         'help'   => self::$Modules['help'],
 135                                         );
 136                         }
 137                 }
 138
 139                 global $wgAPIModules, $wgEnableWriteAPI; // extension modules
 140                 $this->mModules = $wgAPIModules + self :: $Modules;
 141                 if($wgEnableWriteAPI)
 142                         $this->mModules += self::$WriteModules;
 143
 144                 $this->mModuleNames = array_keys($this->mModules); // todo: optimize
 145                 $this->mFormats = self :: $Formats;
 146                 $this->mFormatNames = array_keys($this->mFormats); // todo: optimize
 147
 148                 $this->mResult = new ApiResult($this);
 149                 $this->mShowVersions = false;
 150                 $this->mEnableWrite = $enableWrite;
 151
 152                 $this->mRequest = & $request;
 153
 154                 $this->mSquidMaxage = 0;
 155         }
 156
 157         /**
 158          * Return true if the API was started by other PHP code using FauxRequest
 159          */
 160         public function isInternalMode() {
 161                 return $this->mInternalMode;
 162         }
 163
 164         /**
 165          * Return the request object that contains client's request
 166          */
 167         public function getRequest() {
 168                 return $this->mRequest;
 169         }
 170
 171         /**
 172          * Get the ApiResult object asscosiated with current request
 173          */
 174         public function getResult() {
 175                 return $this->mResult;
 176         }
 177
 178         /**
 179          * This method will simply cause an error if the write mode was disabled for this api.
 180          */
 181         public function requestWriteMode() {
 182                 if (!$this->mEnableWrite)
 183                         $this->dieUsage('Editing of this site is disabled. Make sure the $wgEnableWriteAPI=true; ' .
 184                         'statement is included in the site\'s LocalSettings.php file', 'noapiwrite');
 185         }
 186
 187         /**
 188          * Set how long the response should be cached.
 189          */
 190         public function setCacheMaxAge($maxage) {
 191                 $this->mSquidMaxage = $maxage;
 192         }
 193
 194         /**
 195          * Create an instance of an output formatter by its name
 196          */
 197         public function createPrinterByName($format) {
 198                 return new $this->mFormats[$format] ($this, $format);
 199         }
 200
 201         /**
 202          * Execute api request. Any errors will be handled if the API was called by the remote client.
 203          */
 204         public function execute() {
 205                 $this->profileIn();
 206                 if ($this->mInternalMode)
 207                         $this->executeAction();
 208                 else
 209                         $this->executeActionWithErrorHandling();
 210                 $this->profileOut();
 211         }
 212
 213         /**
 214          * Execute an action, and in case of an error, erase whatever partial results
 215          * have been accumulated, and replace it with an error message and a help screen.
 216          */
 217         protected function executeActionWithErrorHandling() {
 218
 219                 // In case an error occurs during data output,
 220                 // clear the output buffer and print just the error information
 221                 ob_start();
 222
 223                 try {
 224                         $this->executeAction();
 225                 } catch (Exception $e) {
 226                         //
 227                         // Handle any kind of exception by outputing properly formatted error message.
 228                         // If this fails, an unhandled exception should be thrown so that global error
 229                         // handler will process and log it.
 230                         //
 231
 232                         $errCode = $this->substituteResultWithError($e);
 233
 234                         // Error results should not be cached
 235                         $this->setCacheMaxAge(0);
 236
 237                         $headerStr = 'MediaWiki-API-Error: ' . $errCode;
 238                         if ($e->getCode() === 0)
 239                                 header($headerStr, true);
 240                         else
 241                                 header($headerStr, true, $e->getCode());
 242
 243                         // Reset and print just the error message
 244                         ob_clean();
 245
 246                         // If the error occured during printing, do a printer->profileOut()
 247                         $this->mPrinter->safeProfileOut();
 248                         $this->printResult(true);
 249                 }
 250
 251                 // Set the cache expiration at the last moment, as any errors may change the expiration.
 252                 // if $this->mSquidMaxage == 0, the expiry time is set to the first second of unix epoch
 253                 $expires = $this->mSquidMaxage == 0 ? 1 : time() + $this->mSquidMaxage;
 254                 header('Expires: ' . wfTimestamp(TS_RFC2822, $expires));
 255                 header('Cache-Control: s-maxage=' . $this->mSquidMaxage . ', must-revalidate, max-age=0');
 256
 257                 if($this->mPrinter->getIsHtml())
 258                         echo wfReportTime();
 259
 260                 ob_end_flush();
 261         }
 262
 263         /**
 264          * Replace the result data with the information about an exception.
 265          * Returns the error code
 266          */
 267         protected function substituteResultWithError($e) {
 268
 269                         // Printer may not be initialized if the extractRequestParams() fails for the main module
 270                         if (!isset ($this->mPrinter)) {
 271                                 // The printer has not been created yet. Try to manually get formatter value.
 272                                 $value = $this->getRequest()->getVal('format', self::API_DEFAULT_FORMAT);
 273                                 if (!in_array($value, $this->mFormatNames))
 274                                         $value = self::API_DEFAULT_FORMAT;
 275
 276                                 $this->mPrinter = $this->createPrinterByName($value);
 277                                 if ($this->mPrinter->getNeedsRawData())
 278                                         $this->getResult()->setRawMode();
 279                         }
 280
 281                         if ($e instanceof UsageException) {
 282                                 //
 283                                 // User entered incorrect parameters - print usage screen
 284                                 //
 285                                 $errMessage = array (
 286                                 'code' => $e->getCodeString(),
 287                                 'info' => $e->getMessage());
 288
 289                                 // Only print the help message when this is for the developer, not runtime
 290                                 if ($this->mPrinter->getIsHtml() || $this->mAction == 'help')
 291                                         ApiResult :: setContent($errMessage, $this->makeHelpMsg());
 292
 293                         } else {
 294                                 //
 295                                 // Something is seriously wrong
 296                                 //
 297                                 $errMessage = array (
 298                                         'code' => 'internal_api_error_'. get_class($e),
 299                                         'info' => "Exception Caught: {$e->getMessage()}"
 300                                 );
 301                                 ApiResult :: setContent($errMessage, "\n\n{$e->getTraceAsString()}\n\n");
 302                         }
 303
 304                         $this->getResult()->reset();
 305                         $this->getResult()->addValue(null, 'error', $errMessage);
 306
 307                 return $errMessage['code'];
 308         }
 309
 310         /**
 311          * Execute the actual module, without any error handling
 312          */
 313         protected function executeAction() {
 314
 315                 $params = $this->extractRequestParams();
 316
 317                 $this->mShowVersions = $params['version'];
 318                 $this->mAction = $params['action'];
 319
 320                 // Instantiate the module requested by the user
 321                 $module = new $this->mModules[$this->mAction] ($this, $this->mAction);
 322
 323                 if( $module->shouldCheckMaxlag() && isset( $params['maxlag'] ) ) {
 324                         // Check for maxlag
 325                         global $wgLoadBalancer, $wgShowHostnames;
 326                         $maxLag = $params['maxlag'];
 327                         list( $host, $lag ) = $wgLoadBalancer->getMaxLag();
 328                         if ( $lag > $maxLag ) {
 329                                 if( $wgShowHostnames ) {
 330                                         ApiBase :: dieUsage( "Waiting for $host: $lag seconds lagged", 'maxlag' );
 331                                 } else {
 332                                         ApiBase :: dieUsage( "Waiting for a database server: $lag seconds lagged", 'maxlag' );
 333                                 }
 334                                 return;
 335                         }
 336                 }
 337
 338                 if (!$this->mInternalMode) {
 339                         // Ignore mustBePosted() for internal calls
 340                         if($module->mustBePosted() && !$this->mRequest->wasPosted())
 341                                 $this->dieUsage("The {$this->mAction} module requires a POST request", 'mustbeposted');
 342
 343                         // See if custom printer is used
 344                         $this->mPrinter = $module->getCustomPrinter();
 345                         if (is_null($this->mPrinter)) {
 346                                 // Create an appropriate printer
 347                                 $this->mPrinter = $this->createPrinterByName($params['format']);
 348                         }
 349
 350                         if ($this->mPrinter->getNeedsRawData())
 351                                 $this->getResult()->setRawMode();
 352                 }
 353
 354                 // Execute
 355                 $module->profileIn();
 356                 $module->execute();
 357                 $module->profileOut();
 358
 359                 if (!$this->mInternalMode) {
 360                         // Print result data
 361                         $this->printResult(false);
 362                 }
 363         }
 364
 365         /**
 366          * Print results using the current printer
 367          */
 368         protected function printResult($isError) {
 369                 $printer = $this->mPrinter;
 370                 $printer->profileIn();
 371
 372                 /* If the help message is requested in the default (xmlfm) format,
 373                  * tell the printer not to escape ampersands so that our links do
 374                  * not break. */
 375                 $params = $this->extractRequestParams();
 376                 $printer->setUnescapeAmps ( ( $this->mAction == 'help' || $isError )
 377                                 && $params['format'] == ApiMain::API_DEFAULT_FORMAT );
 378
 379                 $printer->initPrinter($isError);
 380
 381                 $printer->execute();
 382                 $printer->closePrinter();
 383                 $printer->profileOut();
 384         }
 385
 386         /**
 387          * See ApiBase for description.
 388          */
 389         public function getAllowedParams() {
 390                 return array (
 391                         'format' => array (
 392                                 ApiBase :: PARAM_DFLT => ApiMain :: API_DEFAULT_FORMAT,
 393                                 ApiBase :: PARAM_TYPE => $this->mFormatNames
 394                         ),
 395                         'action' => array (
 396                                 ApiBase :: PARAM_DFLT => 'help',
 397                                 ApiBase :: PARAM_TYPE => $this->mModuleNames
 398                         ),
 399                         'version' => false,
 400                         'maxlag'  => array (
 401                                 ApiBase :: PARAM_TYPE => 'integer'
 402                         ),
 403                 );
 404         }
 405
 406         /**
 407          * See ApiBase for description.
 408          */
 409         public function getParamDescription() {
 410                 return array (
 411                         'format' => 'The format of the output',
 412                         'action' => 'What action you would like to perform',
 413                         'version' => 'When showing help, include version for each module',
 414                         'maxlag' => 'Maximum lag'
 415                 );
 416         }
 417
 418         /**
 419          * See ApiBase for description.
 420          */
 421         public function getDescription() {
 422                 return array (
 423                         '',
 424                         '',
 425                         '******************************************************************',
 426                         '**                                                              **',
 427                         '**  This is an auto-generated MediaWiki API documentation page  **',
 428                         '**                                                              **',
 429                         '**                  Documentation and Examples:                 **',
 430                         '**               http://www.mediawiki.org/wiki/API              **',
 431                         '**                                                              **',
 432                         '******************************************************************',
 433                         '',
 434                         'Status:          All features shown on this page should be working, but the API',
 435                         '                 is still in active development, and  may change at any time.',
 436                         '                 Make sure to monitor our mailing list for any updates.',
 437                         '',
 438                         'Documentation:   http://www.mediawiki.org/wiki/API',
 439                         'Mailing list:    http://lists.wikimedia.org/mailman/listinfo/mediawiki-api',
 440                         'Bugs & Requests: http://bugzilla.wikimedia.org/buglist.cgi?component=API&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&order=bugs.delta_ts',
 441                         '',
 442                         '',
 443                         '',
 444                         '',
 445                         '',
 446                 );
 447         }
 448
 449         /**
 450          * Returns an array of strings with credits for the API
 451          */
 452         protected function getCredits() {
 453                 return array(
 454                         'This API is being implemented by Roan Kattouw <Firstname>.<Lastname>@home.nl',
 455                         'Please send your comments, suggestions and questions to mediawiki-api@lists.wikimedia.org',
 456                         'or file a bug report at http://bugzilla.wikimedia.org/'
 457                 );
 458         }
 459
 460         /**
 461          * Override the parent to generate help messages for all available modules.
 462          */
 463         public function makeHelpMsg() {
 464
 465                 $this->mPrinter->setHelp();
 466
 467                 // Use parent to make default message for the main module
 468                 $msg = parent :: makeHelpMsg();
 469
 470                 $astriks = str_repeat('*** ', 10);
 471                 $msg .= "\n\n$astriks Modules  $astriks\n\n";
 472                 foreach( $this->mModules as $moduleName => $unused ) {
 473                         $module = new $this->mModules[$moduleName] ($this, $moduleName);
 474                         $msg .= self::makeHelpMsgHeader($module, 'action');
 475                         $msg2 = $module->makeHelpMsg();
 476                         if ($msg2 !== false)
 477                                 $msg .= $msg2;
 478                         $msg .= "\n";
 479                 }
 480
 481                 $msg .= "\n$astriks Formats  $astriks\n\n";
 482                 foreach( $this->mFormats as $formatName => $unused ) {
 483                         $module = $this->createPrinterByName($formatName);
 484                         $msg .= self::makeHelpMsgHeader($module, 'format');
 485                         $msg2 = $module->makeHelpMsg();
 486                         if ($msg2 !== false)
 487                                 $msg .= $msg2;
 488                         $msg .= "\n";
 489                 }
 490
 491                 $msg .= "\n*** Credits: ***\n   " . implode("\n   ", $this->getCredits()) . "\n";
 492
 493
 494                 return $msg;
 495         }
 496
 497         public static function makeHelpMsgHeader($module, $paramName) {
 498                 $modulePrefix = $module->getModulePrefix();
 499                 if (!empty($modulePrefix))
 500                         $modulePrefix = "($modulePrefix) ";
 501
 502                 return "* $paramName={$module->getModuleName()} $modulePrefix*";
 503         }
 504
 505         private $mIsBot = null;
 506         private $mIsSysop = null;
 507         private $mCanApiHighLimits = null;
 508
 509         /**
 510          * Returns true if the currently logged in user is a bot, false otherwise
 511          * OBSOLETE, use canApiHighLimits() instead
 512          */
 513         public function isBot() {
 514                 if (!isset ($this->mIsBot)) {
 515                         global $wgUser;
 516                         $this->mIsBot = $wgUser->isAllowed('bot');
 517                 }
 518                 return $this->mIsBot;
 519         }
 520
 521         /**
 522          * Similar to isBot(), this method returns true if the logged in user is
 523          * a sysop, and false if not.
 524          * OBSOLETE, use canApiHighLimits() instead
 525          */
 526         public function isSysop() {
 527                 if (!isset ($this->mIsSysop)) {
 528                         global $wgUser;
 529                         $this->mIsSysop = in_array( 'sysop', $wgUser->getGroups());
 530                 }
 531
 532                 return $this->mIsSysop;
 533         }
 534
 535         public function canApiHighLimits() {
 536                 if (!isset($this->mCanApiHighLimits)) {
 537                         global $wgUser;
 538                         $this->mCanApiHighLimits = $wgUser->isAllowed('apihighlimits');
 539                 }
 540
 541                 return $this->mCanApiHighLimits;
 542         }
 543
 544         public function getShowVersions() {
 545                 return $this->mShowVersions;
 546         }
 547
 548         /**
 549          * Returns the version information of this file, plus it includes
 550          * the versions for all files that are not callable proper API modules
 551          */
 552         public function getVersion() {
 553                 $vers = array ();
 554                 $vers[] = 'MediaWiki ' . SpecialVersion::getVersion();
 555                 $vers[] = __CLASS__ . ': $Id$';
 556                 $vers[] = ApiBase :: getBaseVersion();
 557                 $vers[] = ApiFormatBase :: getBaseVersion();
 558                 $vers[] = ApiQueryBase :: getBaseVersion();
 559                 $vers[] = ApiFormatFeedWrapper :: getVersion(); // not accessible with format=xxx
 560                 return $vers;
 561         }
 562
 563         /**
 564          * Add or overwrite a module in this ApiMain instance. Intended for use by extending
 565          * classes who wish to add their own modules to their lexicon or override the
 566          * behavior of inherent ones.
 567          *
 568          * @access protected
 569          * @param $mdlName String The identifier for this module.
 570          * @param $mdlClass String The class where this module is implemented.
 571          */
 572         protected function addModule( $mdlName, $mdlClass ) {
 573                 $this->mModules[$mdlName] = $mdlClass;
 574         }
 575
 576         /**
 577          * Add or overwrite an output format for this ApiMain. Intended for use by extending
 578          * classes who wish to add to or modify current formatters.
 579          *
 580          * @access protected
 581          * @param $fmtName The identifier for this format.
 582          * @param $fmtClass The class implementing this format.
 583          */
 584         protected function addFormat( $fmtName, $fmtClass ) {
 585                 $this->mFormats[$fmtName] = $fmtClass;
 586         }
 587
 588         /**
 589          * Get the array mapping module names to class names
 590          */
 591         function getModules() {
 592                 return $this->mModules;
 593         }
 594 }
 595
 596 /**
 597  * This exception will be thrown when dieUsage is called to stop module execution.
 598  * The exception handling code will print a help screen explaining how this API may be used.
 599  *
 600  * @addtogroup API
 601  */
 602 class UsageException extends Exception {
 603
 604         private $mCodestr;
 605
 606         public function __construct($message, $codestr, $code = 0) {
 607                 parent :: __construct($message, $code);
 608                 $this->mCodestr = $codestr;
 609         }
 610         public function getCodeString() {
 611                 return $this->mCodestr;
 612         }
 613         public function __toString() {
 614                 return "{$this->getCodeString()}: {$this->getMessage()}";
 615         }
 616 }
 617
 618